Melting furnace



6, 1939. P MARX 2,161,181

l MELTING FURNAGE Filed NOV. 4, 1957 Patented June 6, 1939 umm-:DASTATES PATENToFFlcr;

2,161,181 MELTING FURNAUE Peter Marx, Hennef-on-thc-Sieg, GermanyApplication November 4, 1937, Serial No. 172,659

'- In Germany November 12, 1936 .z claims. (o1. zes- 9) The inventionrelates to melting furnaces for iron, steel and the like, and moreparticularly to the type adapted to be fired with powdered fuel.

One object of the invention is to provide a furnace comprising a cupolaor stack for melting the constituents of the metal and a refiningchamber into which the melted metal flows from the stack, and which isadaptedv to and has sumcient capacity for highly heating the metal forthe 10 vproduction of metal of high quality and to overl5 ber andproducing high come certain disadvantages and insufciencies inherent inprior furnaces of this type.

Another object of the invention is to provide for retaining the hotgases in the refining chamtemperatures and efficient refining of themetal in the refining chamber by means of a tangential duct between thestack and the refining chamber` with openwork refractory in the ductwhich delivers the hot gases into the stack for distribution throughoutthe crosssectional area of the stack for rapid melting and also forheatingthe metal from the stack to the refining chamber.

Other objects of the invention will appear from 25 the detailed.description.

The invention consists in the several novel features which arehereinafter set forth and are more particularly defined by claims at theconclusion hereof. f. y

In the drawing: Fig. 1 is a vertical section of a melting furnaceembodying the invention, on line of Fig. 2. Fig. 2 is a horizontalsection on line 2-2 of Fig.l. Fig. 3 isua plan of the remov-l ablehearth of the refining chamber.

35 The invention is exemplified in a furnace com- 50 deliver prising acircular cupola or stack I6 into which the charge of materials to bermelted for iron, steel or.other metal, is fed and in the lower end ofwhich they are melted. This stack is provided .with a removable bottom II covered by refractory I2 to provide access to the cupola for repairs.A circular refining chamber I3 is set from the cupola, and comprises aconvex roof I4 and a depending annular wall I5 which is built integrallywith, or as an extension of, the wall of the stack I0. 'The stack andrefining chamber are built of refractory material. A duct I6 leadstangentially from the refining chamber I3 and tangentially into thelower end of the stack I to the combustion gases into the stack. DuctI6. is inclined downwardly from the cupola, and passes through the sideof dependingvwall I5 of the refining chamber. Duct I6 has an inclinedand stepped bottom I1 over which the melted metal from thel stack willslowly flow into the between the horizontally oifrefining chamber.Y DuctI6 is filled with openwork refractory I8 to retard the flow of heat fromthe rening chamber sufficiently so in said chamber will be highly heatedfor the p roduction of highly refined metal, while permitting theremainder to pass into the stack and melt the material inthe stack. The.refining chamber also comprises a hearth I9 with a central dome 20andan upstanding annular wall 2| conforming to the wall I5 dependingfrom the roof I4 of the refining chamber. This forms an annular spacecylindrical circular wall 2| and the dome for the metal being refined.

A series of three ducts 22 extend through the depending wall I5 of therening chamber, for the burners for delivering blasts of fuel,preferably powdered fuel, for axes of these openings are arranged toblow the fuel tangentially into the refining chamber and cause it toswirl around, and over the metal on the hearth in the annular spacearound the dome.

The tangential delivery of the fuel under pressure through openings 22will cause the products of combustionto travel in a circular path overthe metal on the hearth to heat and agitate the metal to a high degree',so as to eliminatethe sulphur and carbon and produce pure metal of' ahigh quality. The `hot gases, after heating the bath in the refiningchamber,l pass tangentially through duct I6 from said chamber into'vthestack I0. The tangential course 'of the cupola and contact with therefractory I8 and walls of duct I6, cause the gases to contactthoroughly with. the charge in the stack and results in full utilizationof the heat-units contained in the gases.

A duct 24 is formed inthe annular side wall 2| and leads outwardly fromthe refining chamber, for discharging slag and ash while the furnace isin operation. This outlet is controlled by a suitable valve 25 so thatthe escape of hot gases from the refining chamber may be controlled, andto discharge the slag when necessary. The circular blast of the gases inthe refining chamber blows the ash over', and the slag on, the meltedmetal on the hearth so it will traverse a circular course with themetal. Abaiiie 26 projects inwardly from the wall 2| and is adapted toskim off the slag and deflect it to the tangential discharge opening 24.An opening 23 is formed in the side wall 2| for drawing off the refinedmelted metal from the hearth I9. f

The hearth of te refining chamber with its annular wall 2i is separatelybuilt from the roof M and its depending Wall I5 and is suitablysupported so it can be lowered onto a wheeled truck that the melt firingthe furnace. The

21 to permit it to be transported toand from the upper section. Thismakes the hearth conveniently accessible for repair or relining. A plug29 is provided in the hearth so the residue in the refining chamber canbe discharged from the hearth.

In operation of the furnace, the charge or' metal and materials to bemelted is fed into the stack I0. The blasts of fuel delivered underpressure into the refining .chamber through inlets 22 cause thecombustion gases to travel in a. circular path indicated by arrows inFig. 2 so the melted metal will be highly heated and refined. From therefining chamber the hot gases pass tangentially through duct I6 andaround the refractory I8, and into the lower porti'on of the -stack I0and melt the charge therein from its bottom upward. These tangentiallyto contact gases enter the cupola with all portions of the charge in thestack. The refractory material I8 in the duct I6 retards the iiow of thehot gases suiiiciently to maintain a very high temperature intherefining chamber. 'The lower portion of the charge in the stackprogressively melts and slowly trickles over the stepped floor I1 ofduct I6 into the refining chamber and onto hearth I9. The dome 20confines the melted metal to the annular space between the annular wall2| and the dome. -The cross-sectional shape of the melted;

metal over the hearth win be suchthat its topf surface will be ofgreater area than the portion beneath it, to provide ample space for theslag and impurities to be released from the melt in the refiningchamber. f.

The circular blast in the refining chamber over the melt produces acircular motion of the metal and slag over the hearth. 'I'he baffle 26skims the slag oi the surface of the circularly-moving melt and deiiectsit to the discharge duct 24 which leads tangentially from the reningchamber. The'discharge through duct 24 is controlled by means of valve25 to avoid unnecessary escape of heat from the rening chamber. Thevalve 25 may be left open sufficiently to permit the slag, ash andimpurities to be discharged continuously during the operation of thefurnace or may be intermittently opened.

, The furnace is adapted for continuous melting because the stack may bekept charged with metal and materials since they are melted at thebottom of the stack and then flow through the duct I6 to the reningchamber. The refined material can be discharged during the refining andmelting operation.

A characteristic of the refining chamber is that the space above themelt is clear and unobstructed, and this provides ample combustion areafor highly heating the melt during the refinement.

The invention is not to be understood as restricted to the details setforth, since these may be modified within the scope of the appendedclaims, without departing from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire 'tosecure by Letters Patent is:

1. In a melting furnace for metals, the combination of a vertical stackfor retaining the charge to be melted, a round refining chamber belowand oiiset horizontally relatively to the stack, means for deliveringfuel tangentially into the refining chamber to cause the products ofcombustion to swirl around the rening chamber, and a duct leadingtangentially from the refining chamber to the bottom of the stack, fordelivering the products of combustion fromv the refining chamber intothe stack to melt .the charge and for conducting the melted metal fromthe stack to the refining chamber.

2. In a melting furnace for metals, the combination of a vertical stackfor retaining the charge to be melted, a round rening chamber Y belowand offset horizontally relatively to the stack, means for deliveringfuel tangentially into the reningchamber to cause the products ofcombustion to swirl around the refining chamber, and a duct leadingtangentially from the refining chamber and tangentially into the bottomof the stack, for delivering the products of combustion from therefining chamber into the stack to melt the charge and for conductingthe melted 45 metal from the stack to the reiining chamber.

.2 PE'I'ER MARX.

